Self correcting oven technology
A reflow soldering oven for soldering and/or bonding component leads both electrically and mechanically to pads on a PCB in an SMT manufacturing system. The soldering oven includes at least one thermal infrared camera that generates thermal images of the PCB to provide thermal imaging processing to monitor and correct temperature deviations in real time. The oven generates a heat map using the thermal images and compares the heat map to a thermal gradient to provide real time profiling and to initiate changes like temperature control or the oven belt-speed monitoring to offer self-correcting capabilities.
1 . A surface mount technology (SMT) manufacturing system for fabricating printed circuit board assemblies (PCBAs), said system comprising:
a printer for depositing solder paste on conductive solder pads on a printed circuit board (PCB);
a pick-and-place machine for placing circuit components on the solder paste;
a reflow soldering oven for bonding component leads both electrically and mechanically to the pads on the PCB, said soldering oven including at least one thermal infrared camera that generates thermal images of the PCB; and
a controller responsive to the thermal images and providing thermal imaging processing to monitor and correct temperature deviations in real time in the soldering oven, wherein the reflow soldering oven provides process data and variables to the controller and the controller provides feedback from upstream processes and inspections to the reflow soldering oven for self-correction purposes, and wherein the printer provides process data and variables to the controller and the controller provides feedback to the printer for self-correction purposes, and wherein the pick-and-place machine provides process data and variables to the controller and the controller provides feedback to the pick-and-place machine for self-correction purposes.
2 . The system according to claim 1 wherein the controller generates a heat map using the thermal images and compares the heat map to a thermal gradient to provide real time profiling.
3 . The system according to claim 2 wherein the controller self-corrects one or more of oven profiles, conveyor speed, heated zones and fan speed in real time.
4 . The system according to claim 1 wherein the at least one thermal infrared camera is a plurality of thermal infrared cameras.
5 . The system according to claim 1 further comprising a solder paste inspection (SPI) sub-system for inspecting the solder paste deposited on the solder pads to identify defects or other issues that would reduce PCB reliability.
6 . The system according to claim 1 further comprising an automated optical inspection (AOI) sub-system for identifying or detecting the presence and volume of inter-metallic compounds in the solder between the components and the solder pads.
7 . The system according to claim 1 further comprising an auto-insertion machine that inserts additional components on the PCB that are not able to be placed by the pick-and-place machine.
8 . The system according to claim 1 further comprising an in-line X-ray inspection machine that performs an X-ray inspection process of the PCB to determine solder coverage.
9 . The system according to claim 8 further comprising a rework machine that corrects solder flows if the PCB does not pass the X-ray inspection process.
10 . The system according to claim 1 further comprising an in-circuit testing machine that provides electrical testing of the PCB.
11 . The system according to claim 1 wherein the printer is a screen printer.
12 . A surface mount technology (SMT) manufacturing system for fabricating printed circuit board assemblies (PCBAs), said system comprising:
a screen printer for depositing solder paste on conductive solder pads on a printed circuit board (PCB);
a pick-and-place machine for placing circuit components on the solder paste;
a reflow soldering oven for bonding component leads both electrically and mechanically to the pads on the PCB, said soldering oven including at least one thermal infrared camera that generates thermal images of the PCB;
a solder paste inspection (SPI) sub-system for inspecting the solder paste deposited on the solder pads to identify defects or other issues that would reduce PCB reliability;
an automated optical inspection (AOI) sub-system for identifying or detecting the presence and volume of inter-metallic compounds in the solder between the components and the solder pads;
an auto-insertion machine that inserts additional components on the PCB that are not able to be placed by the pick-and-place machine;
an in-line X-ray inspection machine that performs an X-ray inspection process of the PCB to determine solder coverage;
a rework machine that corrects solder flows if the PCB does not pass the X-ray inspection process;
an in-circuit testing machine that provides electrical testing of the PCB; and
a controller responsive to signals from and providing signals to the pick-and-place machine, the reflow soldering oven, the SPI sub-system, the AOI sub-system, the auto-insertion machine, the in-line X-ray inspection machine, the rework machine and the in-circuit testing machine, and providing system self correcting features, wherein the reflow soldering oven provides process data and variables to the controller and the controller provides feedback from upstream processes and inspections to the reflow soldering oven for self-correction purposes, and wherein the printer provides process data and variables to the controller and the controller provides feedback to the printer for self-correction purposes, and wherein the pick-and-place machine provides process data and variables to the controller and the controller provides feedback to the pick-and-place machine for self-correction purposes.
13 . The system according to claim 12 wherein the controller is responsive to the thermal images and provides thermal imaging processing to monitor and correct temperature deviations in real time in the soldering oven.
14 . The system according to claim 13 wherein the controller generates a heat map using the thermal images and compares the heat map to a thermal gradient to provide real time profiling.
15 . The system according to claim 14 wherein the controller self-corrects one or more of oven profiles, conveyor speed, heated zones and fan speed in real time.
16 . The system according to claim 12 wherein the at least one thermal infrared camera is a plurality of thermal infrared cameras.